Effects of heating rate and sintering temperature on the tensile properties of sintered γ-Ti/Al nanoparticle chains

Abstract This paper presents the results of molecular dynamics simulations that were performed to numerically study the laser sintering process and mechanical behavior of γ-Ti/Al bimetallic alloy nanoparticles (NPs). The study systematically investigates the effects of heating rate and sintering temperature on the resultant uniaxial tensile performances of the sintered NPs. A chain model was formed by connecting three pre-equilibrated Ti/Al NPs via necks during solid-state sintering. The solid-state sintered chain samples were heated to 1798 K using four different heating rates (0.04, 0.2, 0.5, and 1.0 K/ps). After high-temperature relaxation of selected sintering temperature cases (e.g., 398 K, 598 K, etc. with a 200 K interval) for 10 ns, the heat sintered chain samples underwent a solidification process with a cooling rate of 0.08 K/ps and maintained at 298 K for an additional 1 ns. The resulting sintered chain products were then subjected to uniaxial tension at a strain rate of 0.0001/ps. The thermodynamic properties and crystallographic deformation were investigated during the sintering and subsequent tension processes. Analysis of the yield strengths obtained from the tension tests revealed a statistically significant correlation between the tensile strength of the sintered NPs and the pre-established sintering temperatures at each temperature. This observation indicates that higher sintering temperatures strengthen the neck connections within the NP-chains, leading to greater tensile strength. The higher sintering temperatures can reinforce the neck during high-temperature relaxation. It is worth noting that the effect of heating rates on mechanical properties was less pronounced when the sintering temperature was constant.